A Wicker-McDaniel battle before the June GOP primary could reprise many of the internecine attacks that played out in Alabama, where conservative former judge Roy Moore defeated Sen. Luther Strange, only to lose the general election to Democrat Doug Jones. And it would force national Republicans to contend with yet another fraught party fight as the 2018 congressional election season ramps up.

Trump would have to determine how vocal and visible a role he would be willing to play for Wicker after his political brand took a hit in Alabama, where he backed both losing candidates. Some White House aides are hoping the president will stay out of Mississippi if it becomes a messy primary.

But Senate Majority Leader Mitch McConnell (R-Ky.) has encouraged Trump to back Wicker, and in an October call the president privately assured Wicker of his support, according to two White House officials and a Republican close to the senator, who spoke on the condition of anonymity to describe the private conversation. On the call, Trump noted that he is popular in Mississippi and could be of help in the state. The president did not seem very familiar with McDaniel, these people said.